February 28, 2018

expert reaction to assessments of neonics as published by EFSA

The European Food Safety Authority has published a new assessment that concludes that most uses of neonicotinoid pesticides represent a risk to wild bees and honeybees.

Prof Dave Goulson, Professor of Biology at the University of Sussex, said:

“EFSA has finally published its long-awaited three-part report on the risks posed by three neonicotinoid insecticides (imidacloprid, clothianidin, thiamethoxam) to bees. This is a substantial update to the report EFSA published in 2013, which was focussed on risk to honeybees. The new report incorporates the many new scientific studies published in the last 5 years, plus it specifically considers impacts on wild bees (bumblebees and solitary bees) as well as domesticated honeybees.

“This was clearly a long exercise, taking over two years, involving detailed appraisal of 588 scientific experiments from the literature, and involved repeated consultation with external experts. EFSA’s conclusions are in line with a number of other reviews of this topic published by independent scientists in the last year^1-2 and with a 2015 European Academy of Science Advisory Council Report³.

“In essence, the new EFSA report concludes that neonicotinoids are very likely to be harming both wild and domesticated bees. The evidence is stronger than in 2013. As the report states “Most uses of neonicotinoid pesticide represent a risk to wild bees and honeybees” and “overall the risk to the three types of bees we assessed [honeybees, bumblebees and solitary bees] is confirmed”. There seem to be no uses of neonicotinoids in outdoor situations that were judged to pose a low risk to all groups of bees.

“Since 2013, it has become clear that neonicotinoids do not only pose a risk to bees when used on flowering crops (the subject of the current moratorium). They can pose a risk to bees via contamination of follow-on crops (judged to pose a high risk to honeybees and bumblebees) and via contamination of wildflowers in field margins (also judged to pose a high risk to honeybees and bumblebees).

“The report also highlights remaining knowledge gaps, which are considerable. This is inevitable, given that there are nearly 2,000 species of bee in Europe, most of which have never been studied with regard to impacts of pesticides, and given also that neonicotinoids are used on numerous different crops and in different ways. It was not possible for EFSA to evaluate the risks posed by certain uses of neonicotinoids on particular crops since data were sparse or absent.

“This report certainly strengthens the case for further restrictions on neonicotinod use across Europe.”

1. Wood, T & Goulson, D. 2017. The environmental risks of neonicotinoid pesticides: a review of the evidence post 2013. Environmental Science & Pollution Research 24: 17285-1732
2. Pisa, L. et al. 2017. An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems. Environmental Science & Pollution Research https://doi.org/10.1007/s11356-017-0341-3
3. EASAC Report 2015 “Ecosystem services, agriculture and neonicotinoids”. https://www.easac.eu/fileadmin/Reports/Easac_15_ES_web_complete_01.pdf

Dr Philip Donkersley, Senior Research Associate at the Lancaster Environment Centre, Lancaster University, said:

“It is reassuring that the EFSA have expanded their assessments to include wild bees (bumblebees and solitary bees) in their evidence base for the effects of neonicotinoids on pollinators.

“All three neonicotinoids evaluated here show high risk for exposing bumblebees through the pollen and nectar that they feed on. This exposure affects solitary bee reproduction, colony viability and learning ability in bumblebees.

“A complete ban on the use of neonicotinoids may not be justified however, as evidence here suggests appropriate use under controlled conditions within greenhouses minimises the risk to all pollinators.”

Dr Christopher Connolly, Reader in Neurobiology at the University of Dundee, said:

“This is an important announcement by EFSA that most uses of neonicotinoids are a risk to all bee species. Importantly they identify that high risk does not result from direct exposure to non-flowering crops, but to subsequent indirect exposure from field margins, adjacent crops and succeeding crops. Therefore, the greatest risk to bees is from chronic exposure due to its persistence and translocation to other flowering plants. Beyond this chronic stress to all beneficial insects, this scenario of constant low-level pollution will also inevitably drive pest resistance. A highly restricted use of neonicotinoids would reduce this environmental stress and retain neonicotinoids as important pest control agents for use in severe situations.”

Declared interests

None to declare.